中文摘要：

根据桂西北喀斯特地区7个国家气象站1951—2011年逐月气象资料，采用Penman—Monteith公式计算逐月参考腾发量（ET0），分析各气象因子及ET0的年际变化特征，并计算ET0对太阳净辐射、气温、风速和相对湿度的敏感系数，探讨ET0近60年的变化成因。结果表明：桂西北地区气温呈小幅升高趋势，温度增长量变化范围为0．004—0．186℃／10a，60年平均气温上升范围为0．024-1．116℃；日照时数、风速及相对湿度呈极显著减少趋势，降雨量减少趋势不显著。敏感性分析表明，桂西北地区ET0最敏感的气象因素为相对湿度，其次为太阳净辐射和气温，风速对其影响最小；气温和太阳辐射的敏感系数呈单峰型分布，夏季较大，风速敏感系数呈单谷型分布，夏季较小，相对湿度敏感系数在雨季较小；桂西北地区日照时数和风速的减少对ET0的负贡献率分别为-3．49％和-1．51％，气温的升高和相对湿度的减少对ET0的正贡献率分别为1．36％和3．36％，负贡献大于正贡献，导致ET0下降。研究阐明了目照时数和风速的减少是引起桂西北ET0变化的主要原因。

英文摘要：

Based on climatic data of 7 meteorological stations in karst areas of northwest Guangxi from 1951 to 2011, Penman-Monteith equation was used to estimate monthly potential evaporation （ET0）. Temporal and spatial variations of climatic variables and ET0 were then analyzed using statistical analysis. Contribution rate analysis was used to analyze the influence factors of ET0. The results showed that there was a warming trend in this region. Regional temperature had increased about 0.024-1.116 ℃ in the last 60 years. The annual mean temperature had increase 0.004-0.186 ℃/10a. ha contrast, there were decrease trends for annual mean precipitation, wind speed, sunshine duration and relative humidity. Furthermore, relative humidity, net shortwave radiation and air temperature were the most sensitive factors. Seasonally, the highest sensitivity coefficients to air temperature and sunshine hours and the lowest sensitivity coefficients to wind speed are both in the summer. The absolute sensitivity coefficients to relative humidity are low in rainy season. The sunshine duration and wind speed impacted ET0 negatively trend and relative humidity and temperature impact ET0 positively. However, larger contribution from sunshine duration and wind speed cause ET0 to decline. Consequently, the change of ET0 was primarily attributed to the significant decrease in sunshine duration and wind speed.